(1) Field of the Invention
The present invention relates to a conveyor motor for use in a differential impulse conveyor. In particular, the present invention relates to a pneumatic conveyor motor which uses pneumatic bellows to provide the reciprocating motion for moving the objects along the conveyor.
(2) Description of the Related Art
Differential impulse conveyors, also known as linear motion conveyors, move objects along a surface or tray by varying the direction and speed of the movement of the surface. The conveyor motor moves the conveyor surface slowly in a forward direction to convey the objects forward. The conveyor motor then moves the conveyor surface quickly in the opposite or backward direction. As the conveyor surface is quickly moved backwards, the objects slide along the surface such that the objects remain in the forward position. The slow forward and fast rearward motion is repeated to move the objects along the surface in the forward direction.
The related art has shown various types of differential impulse conveyors where the conveying surface is driven in the forward direction at a slow speed and is driven in the backward direction at a higher speed. Illustrative are U.S. Pat. Nos. 5,794,757 to Svejkowsky et al.; U.S. Pat. No. 5,850,906 to Dean and U.S. Pat. No. 6,209,713 to Takahashi et al. The conveyors use a variety of different drive motors. However, none of the conveyors use bellows as the drive mechanism.
U.S. Pat. No. 1,146,947 to Norton; U.S. Pat. No. 2,214,755 to Tafel; U.S. Pat. No. 2,473,193 to Campion; and U.S. Pat. No. 4,508,208 to Preedy describe pneumatic transporters or conveyors which use pneumatic cylinders, pistons and seals to provide the drive or momentum for the conveyor. A fluid such as air can be used to move the pistons. However, none of the patents show the use of pneumatic bellows.
Also, of interest is U.S. Pat. No. 2,378,979 to Burt which describes a vibrating conveyor which uses a pressure responsive element such as a bellow or flexible diaphragm to create vibrations which are transferred to a conveyor table. The conveyor of this reference is a vibration conveyor rather than a differential impulse conveyor as in the present invention. Further, the pressure response element of this patent is operated by water.
There remains the need for a differential impulse conveyor which uses pneumatic bellows as the drive motor. Bellows have inherent qualities of low maintenance, tolerance to lateral misalignment, high resistance to contamination and frictionless stroke. Bellows are also capable of generating high forces and need no lubrication. Thus, the use of bellows enables the present invention to be inexpensive to construct and inexpensive to maintain.